1. Technical Field
This invention relates to a connection unit such as an expansion unit for expanding functions of an information processing system such as a personal computer mounted thereon and, more particularly, to an expansion unit for offering a LAN connection environment to an information processing system mounted thereon. More specifically, this invention relates to an expansion unit for offering a WOL (Wake-up On LAN) history displaying function to an information processing system.
2. Description of the Prior Art
Recently, the term “network computing” frequently appears in a variety of media such as newspapers, periodicals and the like. “Network computing” literally means an environment, wherein a plurality of computers and/or peripheral devices are coupled together by a communication medium (whether it be a wired or wireless medium). Also, “network” means a communication network for transmitting data among computers. There are diverse forms of networks, which range from a local area type such as a LAN (Local Area Network) to a wide area type such as a public switched telephone network (PSTN), and further to the “Internet” that has grown into an enormous collection of global networks as a result of interconnecting respective servers. A computer system as a DTE (Data Terminal Equipment) is connected to a network via a DCE (Data Circuit-Terminating Equipment). A DCE is either one of a modem (Modulator/Demodulator), a TA (Terminal Adapter) and a LAN adapter (e.g., Ethernet card or token ring card) depending on whether the network involved is an analog type such as PSTN, ISDN (Integrated Services Digital Network) or a LAN. Also, a DTE may be a general purpose computer system (e.g., an IBM PC/AT compatible machine (“PC/AT” is a trademark of International Business Machines Corporation), besides any dedicated terminal connected to the network via a DCE.
A LAN is a smallest unit of a network, which is autonomously operated/managed by an independent organization such as a college or a research institution to cover a relatively narrow area such as a single campus or the like. Supported with the price reduction of communication equipment reflecting the evolution of semiconductor technologies and the enhanced functions of communication software, LANs have been primarily and deeply used in research/development arenas for the purpose of sharing computer resources, sharing/distribution of information and the like.
The forms of LANs are generally categorized as a peer-to-peer type and a client/server type. In the peer-to-peer LAN, interconnected DTEs have no master/slave relationship among them so that they are treated equally. More particularly, in the peer-to-peer LAN, there exists such relationship among the interconnected DTEs that allows each of them to share a resource of another DTE respectively, whereby a disk and/or a printer owned by a user of a given DTE may be used by another LAN user as it is. On the other hand, in the client/server LAN, a single machine on the LAN is dedicated to be a server, which is to be shared by other LAN users (i.e., clients). In the client/server LAN, the server for offering service and clients for accepting service are synchronized each other by using a remote procedure call (RPC) to continue respective processing.
Today, the client/server LAN that has general purpose personal computers (PCs) interconnected is becoming the mainstream of network computing. This is primarily intended for enjoying the advantages of this scheme as described below.
(1) Installing software that is necessary for each client PC, each user is allowed to freely perform his own work. (2) Data/files to be shared are placed on a server's side. Also, a printer is connected to the server such that each user can share it via the network. (3) Installing software such as groupware onto the server, it is possible to perform processing corresponding to a group work.
However, as a result of excessively distributing information toward a client's side (i.e., client PC is overgrown), it has been found problematic in that maintenance and/or management of the client system requires a vast amount of costs. For example, whenever an OS or an application is to be upgraded, there has been no way to avoid cumbersome manual works such as installation and/or setup for each PC. It is, therefore, mandatory to reduce costs of an entire network, i.e., total cost of ownership (TCO).
One of the known concepts for reducing TCO is to use a server for centrally managing software resources on a network. For example, by simply updating a program on the server, those programs available at clients' sides are automatically updated. By centrally managing from the server's side in this way, it becomes possible to prevent any trouble due to an operational miss on a client's side from occurring, which will in turn lead to reduction of TCO.
As one of the techniques for reducing TCO, it is possible to apply WOL (“Wake-up ON LAN”) in such a way that a system configuration of a client's side can be managed via the network. By automatically activating each client system, which has been powered off, via the network during a convenient time zone such as at night where the office changes to an unattended environment, it becomes possible to install a new application onto each system or to replace an older one with a new one.
In order to implement WOL, it is essential that a DCE to be connected to a network or a LAN is provided with the WOL function. When a DTE as a user terminal is a general purpose computer system, a DCE is provided in the form of a LAN adapter card, for example. The adapter card is insertable into a “bus slot”, which is generally formed on a computer's system unit (at its mother board).
The WOL function is implemented by a function for automatically starting up a computer system via a network or a LAN. In FIG. 6, there is schematically shown a configuration of a WOL compatible computer system. A WOL compatible LAN adapter 610 is connected to a LAN and, upon recognition of a frame packet (hereafter called “wake-up packet”) for indicating activation (i.e., “Wake-up”) of the system that is currently in a stopped state, asserts a WOL signal 660 to the system's side. Also, the WOL compatible computer system is provided with an auxiliary power supply 625, which continually feeds power to the LAN adapter 610 such that a WOL operation is enabled while the system itself is in a power-off state. Further, the computer system is provided with a WOL logic circuit 640, which is responsive to detection of the WOL signal asserted by the WOL compatible LAN adapter 610 for issuing a power-on indication to a power supply circuit 620 for the entire system.
The term “expansion unit” means herein such equipment that is used for expanding a peripheral environment of a notebook PC by simply mounting the PC thereon. In FIG. 7, there is shown a manner of mounting a notebook PC 720 onto an expansion unit 710. For ensuring portability, the notebook PC 720 is designed and manufactured to have a smaller size and a lighter weight at the sacrifice of its peripheral environment. For example, the notebook PC 720 is capable of accommodating a limited number of external storage devices alone, and only PC cards may be inserted therein since it has no bus slot for mounting an adapter card thereon. Note in this respect that it is extremely cumbersome for a user, who carries the notebook PC 720, to attach/detach connection cables for a variety of equipment used in an office environment such as a printer, a CRT (Cathode Ray Tube) display, an external keyboard and the like. The expansion unit 710 is such equipment that offers the same working environment as a desktop PC whenever the notebook PC 720 is used in an office. For this purpose, the expansion unit 710 has a “Port Replication function” and a “Bus Expansion function”.
The port replication function is implemented by having extensions of connection port signals in the notebook PC 720's system unit. If, at the expansion unit 710's side, peripheral devices (not shown) such as a printer, a CRT display and an external keyboard are previously cable connected, a user will be allowed to immediately make use of these peripheral devices by simply mounting the notebook PC 720 onto the expansion unit 710. Also, if these peripheral devices are kept connected to the expansion unit 710, these peripheral devices will be immediately available to another notebook PC 720 mounted on the expansion unit 710 without worrying about the cumbersome works to attach/detach cables. Such a function for centrally managing cable connections may be called a “cable management function”.
On the other hand, the “bus expansion function” is implemented by having at the expansion unit 710's side extensions of buses in the notebook PC 720's system unit (e.g., a PCI (Peripheral Component Interconnect) bus as a local bus and an ISA (Industry Standard Architecture) bus as a system bus). The expansion unit 710 has a space for accommodating one or more external storage devices to be connected to a bus, along with one or more bus slots for mounting one or more adapter cards thereon. Attaching a HDD, a SCSI (Small Computer System Interface) adapter card and a LAN adapter card onto the expansion unit 710, it is possible to offer a file subsystem or a network subsystem to a user of the notebook PC 720. Incidentally, the expansion unit 710 may be called a “docking station”. Also, an expansion unit having the port replication function alone may be called a “port replicator”.
Generally, the expansion unit 710 is used in a “single user mode” or a “multi user mode”. The former means that a single PC user exclusively owns the expansion unit 710, i.e., only a particular notebook PC is exclusively mounted on a single expansion unit 710. On the other hand, the multi user mode means that a plurality of PC users share a single expansion unit 710, i.e., a notebook PC of each user may be interchangeably mounted on the expansion unit 710. In the multi user mode, it may frequently happen that policies and/or strategies differ from user to user.
Incidentally, an expansion unit per se is disclosed, for example, in JA patent application 5-181593 (JA patent publication 7-36577) and JA patent application 6-134124 (JA patent publication 8-6668), each being assigned to the present applicant.
Now, with reference to FIG. 4, operations of a prior system will be described. (1) In a first case where a note PC 409 is connected to a docking station 407: A system administrator sends a WOL packet to a note PC system 410 for activating the system. While, at this point of time, a power supply for the notebook PC 409 of the note PC system 410 is in an off state, its LAN feature section is continually driven by an auxiliary power supply to wait for arrival of a WOL packet. Whenever a WOL packet sent from a server 403 via a network 401 arrives at the notebook PC system 410, a signal (PME# or the like) for activating the system is asserted to start up the power supply for the note PC 409, thereby activating the system. After the system is activated, the system administrator performs maintenance or the like of the note PC 409 using remote control software or the like and, subsequent to termination thereof, shuts down the system to complete a sequence of operations.
(2) In a second case where a note PC 409 is not connected to a docking station 405: The system administrator sends a WOL packet to the docking station 405 for activating the system. Since, at this point of time, the note PC 409 is not connected to the docking station 405, an auxiliary power supply for a LAN feature section within the docking station 405 is in an off state. Accordingly, even if a WOL packet is received, no event will occur at all. Because the note PC 409 is not activated despite sending of the WOL packet, the system administrator will resend the WOL packet. However, the same result will be iterated and, thus, operations will be terminated without completing the intended maintenance or the like.
In many occasions, such WOL operations are executed at night where the office changes to an unattended environment, thereby to prevent routine jobs from being obstructed. In the first case (1) above (where a computer is connected), if it is arranged to activate an application after starting up the system on the next morning to inform the execution of WOL, a user of the PC system 409 to be managed will be able to recognize that its maintenance or the like has been performed by the system administrator. However, with this approach, there is no way to know, before activating the system, whether or not any work such as maintenance has been carried out, nor are all applications designed to inform a user of the fact that such maintenance work has been performed.
Also, in the second case (2) above (where a computer is not connected), while the system administrator has required to manage the PC system 409, nevertheless there is no way for a user of the PC system 409 to know such a situation. On the other hand, in either case (1) or (2) above, there is no way for a user of the PC system 409 to know any history that a malicious third party has either remotely activated or has attempted to remotely activate the system, which may lead to a security problem.